Renewable fuse plug



Feb. 27, 1934. J, wl HOOLEY RENEWABLE FUSE PLUG- F'iled Feb. 7, 1953Patented Feb. 27, 1934 PATENT GFFCE RENEWABLE FUSE PLUG John W. Hooley,Larchmont, N. Y.

Application February 7, 1933.

2 Claims.

This invention relates to devices for effecting quick rfc-connection ofbroken electrical circuits, and refers particularly to what are commonlyknown as fuse plugs.

I Fuse plugs of the present common orwell known type have solderedconnections so that the device as a whole is practically sealed tight atthe factory and can not be taken apart without entirely destroying itsutility. Therefore, if the fuse mem- 10 ber of such a plug blows out dueto overload, short circuit, etc., the entire fuse plug must be thrownaway. When this happens, if one has no new plug of the right kindconveniently at hand, he is liable to attempt to substitute for theblown l5 fuse something to serve as one, with the result that thecircuit may be badly overloaded, or grounded, or short-circuited, andcause great cla-mage, because, after all, the fuse is only a safetyvalve for the protection of the circuit. For such i0 elaborateelectrical devices as are now manufactured and used, such as electricirons, electric heaters, electrical instruments, lamps, fixtures,motors, etc., if the circuit is not properly limited as to itscurrent-'carrying capacity and protected I6 'adequately by just theproper fuse therefor, the result is apt to be not only monetary loss dueto damage to appliances connected to the circuit, but also a rire orpersonal injury. Therefore, a most vital necessity for protection tolife and property 80 is in the proper and immediate operation ofelectric fuses or circuit-protective devices.

One of the objects of my invention is to provide fuse plugs with fusemembers which are easily renewable without affecting the plug itself, sothat loja single plug may be used repeatedly by simply substituting anew fuse member for a blown one, this only necessitating the having athand a small compact plurality of duplicate members of the same kind asthe one blown.

40 j Another object is to eifect economy in space and in the cost tousers, by enabling a single plug and, for instance, a dozen extra fusemembers, to ultimately serve the purpose of thirteen fuse plugs of thepresent type.

45 i Another object is to provide renewable fuse plugs which require nomore space than any of the present well-known types, and which may beutilized in all cut-outs the same as previous types.

With said objects in View, and others hereinoojafter referred to, myinvention consists in the construction and combination of partssubstantially as hereinafter described and claimed.

Of the accompanying drawing:

Figure 1 represents, in vertical section, a pre- 'yferred embodiment ofmy invention.

Serial No. 655,661

Figure 2 is a plan view of the same.

Figure 3 is a perspective view of one of the fuse members, enlarged.

Similar reference characters designate similar parts or features in allof the views. e i

secures the contact member 1'7. l The screw also 70' passes through awasher 18 bearing on the inner surface of the body 12 at its bottom.

Referring now to Figure 3 which illustrates a preferred form for themost important feature of my present invention, the fuse member 19 has'15 slotted ends 20 one of which is adapted to be secured under the headof the screw 16 as illustrated in Figure 1, and the other slotted end isadapted to be secured under the head of an upper screw 21 which extendsthrough the side wall of 80 the body 12 and engages the conducting shell13.

rlhe fuse member is of such length that it can be bent to have anintermediate portion of its length offset laterally so as to extendsomewhat vertically near the side of the body 12 that is op posite thelocation of the screw 21, for a purpose presently described. Said fusemember is preferably of the type illustrated and claimed in Re issueLetters Patent No. 16,503, issued to me December 14, 1926, the said fusemember having openings therein in the form of characters determining andindicating the capacity of the fuse. Said patent may be referred to fora full explanation of the advantages of the fuse being made so as toindicate on its face its current capacity in clear and unmistakableterms.

Movably or removably mounted in the body 12 is a barrier or guard disk22 having a marginal recess 23, preferably of such material as micawhich is sufficiently transparent to permit visible inspection of thecondition of that portion of the fuse member which is below it, andwhich is sufficiently reflective to aid the inspection of the conditionof that portion of the fuse member which is above it, such ins ectionbeing permitted by the transparent disk 1li. As illustrated in Figure 1,the .interior of the body l2 is slightly tapered, and the barrier disk22 is of such diametrical size as to be frictionally retainedsubstantially in a mid-way position so that the portion los;

of the fuse member which extends along near one side of the chamber inthe body 12 will be accommodated in the recess 22 of the barrier.

The washer or guard disk 22 serves to prevent any molten metal thatexists after a blow-out of the fuse 19 from causing or permitting an arcbetween those portions of the fuse remaining adjacent -to the screws.Such jumping of the current would be liable to cause such heat as todamage the cut-out block itself and other adjacent devices orstructures.

The body 12 is provided with a downwardly and outwardly directed venthole 24 to permit gases to escape when the fuse member blows.

The utility and advantages off the device will now be explained:

Assuming that a user purchases and has at hand one or more of therenewable fuse plugs, with a plurality, say six, of duplicate fusestrips of the same kind as the one already in the plug member, then thespace required, and the cost to him, will be far less than for sevenordinary fuse plugs.

Assuming that the fuse becomes blown in the device that is in use, it isapparent and visible through the disk 14. When the device is unscrewedfrom its socket in the fuse block or cutout, the ring l5 is unscrewedand the disk 14 removed. Then a screw-driver can be used to remove thescrew 21, and the washer or barrier 22 is removed. If the latter issomewhat stuck, its removal from its frictionally held seat can bereadily effected by inserting the point of the screw-driver in therecess 23 and loosening said barrier. After then loosening the screw 16,the burnt-out fuse member is removed. A new fuse member 19 then has itslower end secured under the head of the screw 16, the barrier 22returned to the position illustrated (the fuse member being inherentlysuiliciently flexible to permit this to be done), the upper end of thefuse member then secured under the head of the screw 21, and the disk 14and ring 15 returned to position. These operations can be eiiected inapproximately 30 seconds, so that a new fuse quickly takes the place ofa blown one at a fraction of the cost of an entire new fuse plug `ofcommon type.

The vent 24 is directly over the recess 23 in the margin of the guarddisk 22, and said vent extends in a downwardly and outwardly leadingdirection. Therefore, if the fuse is burnt out any gases resultingtherefrom will escape through the vent hole into the air surrounding thefuse plug so as to eliminate possibility of re in the event that anyname is carried as a portion of the gas.

Another advantage is that building owners, engineers, or those in chargeof building operations, can keep in stock a large supply of fuse members19 at relatively low cost as compared with a stock of complete fuseplugs, and requiring but a small space for storage.

Another and important advantage is that correct re-conditioning of ablown-out device is ensured, because the two members consisting of theplug member and the fuse member are of such relative pre-designed shapesor proportions and have such co-acting connecting members as the screws16, 21, and the slotted ends 20 of the fuse strips, that an improperfuse member could not be installed in the plug member.

Having now described my invention, I claim:

l. A renewable fuse plug consisting of a plug member having a taperingchamber, a flash guard disk frictionally engaging the wall of saidtapering chamber at an intermediate point thereof, said guard diskhaving a marginal recess, and a fuse member the upper portion of whichextends transversely across the chamber above said guard disk and anintermediate portion of which extends through the said marginal recessor the guard disk.

2. A renewable fuse plug consisting of a plug member having a. taperingchamber, a flash guard disk frictionally engaging the wall of saidtapering chamber at an intermediate point thereof, said guard diskhaving a marginal recess, and a fuse member the upper portion of whichextends transversely across the chamber above said guard disk and anintermediate portion of which ex tends through the said marginal recessof the guard disk, the plug member having a downwardly and outwardlydirected vent hole in the upper portion of its wall directly over themarginal recess in the guard disk.

JOHN W. HOOLEY.

